Increment preparation error

This triplet gets it collective name (ISE) from the fact that the errors only arise when the sampling process is carried out in an incorrect fashion. The good news is that they can all be virtually eliminated (but only 

IDE and lEE are random variables, whilst IPE is nomandom, being generated accidentally and is hence nonstatistical in nature. 

Whenever increment/sample masses are not identical, estimation of the total lot mass, Al must be done as a weighted mean from the analytical results, lest an additional IWE be introdnced. 

Usnally IWE does not pose grave problems, if snitable countermeasures have been contemplated a priori. In process sampling obtaining a constant increment mass has many advantages, and is thus often given a high priority. For practical purposes, this can be considered effectuated if the relative variation between increment masses remains below, say, 20% [2,3,9,14]. In order not to confuse the process issues needlessly, below we shall assume that all IWE issues have been dealt with properly (i.e. eliminated). 

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IPE increment preparation error MON motor octane number... 

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